System and method for controlling a conveyor system configuration to accommodate different size substrates

ABSTRACT

A rail position control system is provided that controls a conveyor system configuration to accommodate a plurality of differently sized substrates in an apparatus. The rail position control system includes at least one camera, which is mounted on a mounting surface located in close proximity to the conveyor system. The rail position control system further includes a computer system that is operatively coupled to the camera and to a motor. The motor is further coupled to at least one rail of the conveyor system. The camera is operative to view and provide a plurality of images of a conveyor lane width value to the computer system. The conveyor lane width value represents a space located between at least one pair of rails of the conveyor system. The computer system responds by processing the plurality of images of the conveyor lane width value to generate a rail position adjustment value, which is communicated, via control signals, to the motor to actuate the motor to move the at least one rail a distance representing the rail position adjustment value.

RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.09/973,448, entitled SYSTEM AND METHOD FOR CONTROLLING A CONVEYOR SYSTEMCONFIGURATION TO ACCOMMODATE DIFFERENT SIZE SUBSTRATES, filed Oct. 9,2001, now U.S. Pat. No. 6,688,458.

FIELD OF THE INVENTION

The present invention relates generally to a system and method forcontrolling a conveyor system to accommodate differently sizedsubstrates. More specifically, the present invention relates to a systemand method for adjusting conveyor rails of a conveyor system in adispensing system to accommodate differently sized substrates.

BACKGROUND

There are several types of prior art dispensing systems used fordispensing metered amounts of liquid or paste for a variety ofapplications. One such application is in the assembly of printed circuitboards and integrated circuit chips. In this, application, dispensingsystems are used in the process of encapsulating integrated circuitswith an encapsulating material and in the process of underfilling flipintegrated circuit chips with an encapsulant. Prior art dispensingsystems are also used for dispensing dots or balls of liquid epoxy orsolder paste onto circuit boards and integrated circuits. The liquidepoxy and solder is used to connect components to a circuit board or toan integrated circuit. The dispensing systems described above includethose manufactured and distributed by Speedline Technologies, Inc.,assignee of the present invention, under the name CAMALOT™.

The dispensing systems described above are typically used in anelectronics manufacturing facility in an automated assembly line withother equipment used in a circuit board or integrated circuitmanufacturing process. The other equipment in-line with the dispensingsystems may include, for example, pick and place machines, which placecomponents on circuit boards, or reflow ovens that are used to curematerials dispensed onto the circuit boards or integrated circuits.

In a typical dispensing system, a pump and dispenser assembly is mountedto a moving assembly for moving the pump and dispenser assembly alongthree mutually orthogonal axes (x, y, z) using servomotors controlled bya computer system or controller. To dispense a dot of liquid on acircuit board at a desired location, the pump and dispenser assembly ismoved along the horizontal x and y axes until it is located over thedesired location. The pump and dispenser assembly is then lowered alongthe vertical z axis until the nozzle of the pump and dispenser assemblyis at an appropriate dispensing height over the board. The pump anddispenser assembly dispenses a dot of liquid, is then raised along the zaxis, moved along the x and y axes to a new location, and is loweredalong the z axis to dispense the next liquid dot.

During the manufacture of circuit boards, a conveyor system is typicallyemployed to transport the circuit boards through several processingstations associated with the dispensing system. It is sometimesnecessary, or desirable, to process differently sized circuit boards. Asa result, spacing between conveyor rails of the conveyor system requiresadjustment. Typically, an operator of the dispensing system is requiredto physically move the conveyor rails to adjust the spacing of the railsto accommodate the differently sized circuit board. In this arrangement,the operator is required to re-adjust the spacing of the conveyor railseach time a differently sized circuit board is transported on theconveyor rails of the conveyor system.

One deficiency with requiring an operator to re-adjust the conveyorrails of the conveyor system, as described above, relates to reducedoutput of the circuit board manufacturing process. In particular, thecircuit board manufacturing process needs to be stopped for a period oftime to enable the operator to re-adjust the spacing of the conveyorrails. Stopping the circuit board manufacturing process for a period oftime significantly reduces volume production and adds significant coststo the final products produced. Another deficiency of this re-adjustmentrequirement is related to operator error. If the operator fails toprecisely space the rails of the conveyor system, the circuit boards caneither fall off of the conveyor system (e.g. rails spaced to far apart)or the circuit boards can become jammed in other machinery associatedwith the conveyor system (e.g. rails spaced to close together).

Some conveyor systems include motorized rails for reducing operatorintervention during the process of re-adjusting rails of the conveyorsystem. In this type of conveyor system, for example, a motor is coupledto at least a first rail of the conveyor system. The motor is used tomove the first rail relative to an adjacently positioned second rail toadjust a space between the first rail and the second rail to accommodatedifferent size circuit boards. In operation of this conveyor system, themotor is initially controlled to move the first rail to a referenceposition. The motor is thereafter controlled to move the first rail fromthe reference position to a position for carrying the circuit boards,which is a predetermined distance from the reference position. Thepredetermined distance for which the first rail is moved is typicallymeasured by an encoder that is coupled to the motor.

One deficiency with this type of conveyor system relates to the timerequired to initialize the position of the first rail during systemstart-up, after a power loss or after a system reset. Other deficiencieswith this type of conveyor system can occur if the conveyor systemincludes multiple conveyor lanes. The multiple lane conveyor system caninclude a plurality of pairs of rails, for which some or all of therails may require initial positioning at the reference position, aspreviously described. Further, during the course of operations using themultiple lane conveyor system it may become necessary to re-adjust fewerthan all of the lane widths, which would require fewer than all of themotorized rails to return to the reference position and then move to anoperating position.

One deficiency occurs in that adjacent lanes that do not require lanere-adjustment may be positioned intermediate the lane that requiresre-adjustment and the reference position, thus blocking the motorizedrail from moving to the reference position without disturbing theoperating position of the adjacent lanes that do not require lanere-adjustment.

Therefore, a need exists for a control system and method for controllinga conveyor system to precisely adjust conveyor rails of the conveyorsystem to accommodate differently sized substrates, which overcomes thedeficiencies and limitations described above.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide a control system and methodfor controlling a conveyor system configuration to precisely adjustconveyor rails of the conveyor system to accommodate differently sizedsubstrates.

In accordance with one aspect of the present invention, an apparatus forperforming a task on a work piece is provided. The apparatus includes anobject that performs the task on the workpiece, a work surface, aconveyor system mounted on the work surface and having at least a firstrail and at least a second rail separated by a first space equal to afirst conveyor lane width value, a support structure coupled to the worksurface, the support structure being coupled to the object to supportthe object over the conveyor system, at least one camera mounted on thesupport structure, and a processor coupled to the at least one camera.The at least one camera is constructed and arranged to capture a firstimage of a first registration mark associated with the first rail and tocapture a second image of a second registration mark associated with thesecond rail and to provide the first and second images to the processor.Further, the processor is programmed to receive the first and secondimages and determine the first conveyor lane width value.

The conveyor system can further include at least a third rail and atleast a fourth rail separated by a second space equal to a secondconveyor lane width value. The at least one camera can be constructedand arranged to capture a third image of a third registration markassociated with the third rail and to capture a fourth image of a fourthregistration mark associated with the fourth rail and to provide thethird and fourth images to the processor to determine the secondconveyor lane width value. The first registration mark can be located ata first predetermined position on the first rail and the secondregistration mark can be located at a second predetermined position onthe second rail. The apparatus can further include a motor coupled tothe processor and to the first rail, the motor being adapted to receiveand respond to control signals provided by the processor to move thefirst rail a distance based on a first conveyor lane adjustment valuegenerated by the processor. The apparatus can further include at leastone gantry system having a slidably mounted platform adapted to securelyhold the object and to move the object over work pieces on the conveyorsystem. The platform can be further adapted to securely hold the atleast one camera and to move the at least one camera over the conveyorsystem. The object can include a material dispensing head.

Another aspect of the present invention is directed to a method ofcontrolling a conveyor system configuration, having a first rail and asecond rail, to accommodate a plurality of differently sized substrates.The method includes positioning a camera to capture at least one imageof the conveyor system, determining a distance between the first railand the second rail based at least in part on the at least one image,comparing the distance determined with a desired distance, and moving atleast one of the first rail and the second rail to set the distancesubstantially equal to the desired distance.

The method can include positioning a camera to a first position over thefirst rail to capture an image of the first rail, and positioning thecamera to a second position over the second rail to capture an image ofthe second rail. The step of determining a distance can includedetermining a distance between the first position and the secondposition.

Another aspect of the present invention is directed to an apparatus thatpositions an object to perform a task on a work piece. The apparatusincludes the object, a work surface, a support structure positioned overthe work surface and constructed and arranged to support the object overthe work surface, a conveyor system mounted on the work surface andhaving at least a first rail and at least a second rail separated by afirst space equal to a conveyor lane width, and means for viewing theconveyor system and for determining the conveyor lane width.

The apparatus can further include means for moving at least one of thefirst rail and the second rail to adjust the conveyor lane width. Themeans for viewing the conveyor system and for determining the conveyorlane width can include a camera and means for moving the camera to afirst position over the first rail and to a second position over thesecond rail. The means for viewing the conveyor system and fordetermining the conveyor lane width can include means for determining adistance between the first position and the second position.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects of the present invention, the variousfeatures thereof, as well as the invention itself, can be more fullyunderstood from the following description, when read together with theaccompanying drawings in which:

FIG. 1 is a perspective view of a multiple head dispensing system inaccordance with one embodiment of the present invention;

FIG. 2 is a top view of the dispensing system of FIG. 1;

FIG. 3 is a perspective view of a conveyor system used in the dispensingsystem of FIG. 1;

FIG. 4 is a top view of the conveyor system shown in FIG. 3, with a railposition control system for adjusting conveyor rails of the conveyorsystem to accommodate differently sized substrates; and

FIG. 5 is a side view of the conveyor system shown in FIG. 4.

DETAILED DESCRIPTION

For purposes of illustration, embodiments of the present invention willnow be described with reference primarily to a rail position controlsystem and method for adjusting conveyor rails of a conveyor system toaccommodate differently sized substrates, which are transported througha multiple head dispensing system. However, those skilled in the artwill appreciate that embodiments of the present invention are notlimited to multiple head dispensing systems, but can include single headdispensing systems or other systems in which a work device is used toperform some task on a substrate or product. Examples of such systemsinclude test and measuring systems, component placement systems,inspection systems and machining systems, such as milling machines. Inaddition, embodiments of the present invention may include a number ofdifferent types of work devices within one system. For example, a systemmay include a dispensing head, a vision inspection system, and acomponent placement head, each of which may be positioned independentlyusing its own gantry system.

One embodiment of a multiple head dispensing system 10 of the presentinvention will now be described with reference to FIGS. 1-5. FIG. 1shows a perspective view of a multiple head dispensing system 10, whichincorporates a rail position control system 300 for adjusting aplurality of rails 90, 92, 94 and 96 of a conveyor system 20 toaccommodate a plurality of differently sized substrates in accordancewith one embodiment of the present invention. For ease of illustration,the dispensing system 10 is shown in FIG. 1 without an outer covering.FIG. 2 shows a top view of the dispensing system 10. The dispensingsystem 10 can be similar to that shown and described in commonly ownedU.S. Pat. No. 6,007,631, which is hereby incorporated by reference inits entirety.

The dispensing system 10 includes a lower compartment 12 that is used tohouse electrical and pneumatic controllers (not shown) and a primarysystem controller (not shown). Access doors 14 and 16 are mounted on thefront of the lower compartment to provide access to the equipmentcontained therein. The top of the lower compartment forms a work surface18 on which a dual track conveyor 20 resides. Mounted to the worksurface 18 are four x/y gantry systems 22 a, 22 b, 22 c and 22 d. Eachof the gantry systems supports a dispensing head 24 a, 24 b, 24 c and 24d, which dispenses material onto substrates loaded into the dispensingsystem using the conveyor system 20. In one embodiment of the presentinvention, at least one of the gantry systems 22 a, 22 b, 22 c and/or 22d supports a camera 305 (FIGS. 4 and 5), which is used for inspectionand alignment and is also used as part of a rail position control system300 (FIGS. 4 and 5) for adjusting conveyor rails of the conveyor system20 to accommodate differently sized substrates, as is described infurther detail below.

The work surface 18 has four holes through which four cable troughs 26a, 26 b, 26 c and 26 d pass. Each of the cable troughs are used to runcables from the control electronics and pneumatics in the lowercompartment to each of the dispensing heads 24 a, 24 b, 24 c and 24 d.In one embodiment, the cable troughs are implemented using an E-Chainavailable from Igus Corporation.

The gantry systems 22 a, 22 b, 22 c and 22 d are substantiallyidentical. Gantry system 22 a will now be described in greater detailwith reference to FIGS. 1 and 2, it being understood that gantry systems22 b, 22 c and 22 d are substantially identical to gantry system 22 a,as mentioned above. Gantry system 22 a provides positioning of thedispensing head 24 a along the horizontal, orthogonal x and y axes shownin FIG. 1. In addition, gantry system 22 a includes a motor for loweringthe dispensing head in the vertical z direction.

Gantry system 22 a includes two horizontal support members 26 and 28 andfour vertical support members 30, 32, 34 and 36 coupled to the worksurface 18. A motor support plate 38 is coupled between the horizontalsupport members 26 and 28 and is used to support two motors 74 and 76.The gantry 22 a also includes a plate 50 that is slidably mounted torails (not shown) disposed on the under side of each of the horizontalsupport members so that the motor support plate 38 can move along they-axis. Dispensing bead or pump 24 a is mounted to a carriage 60, whichin turn is slidably mounted to the plate 50 to permit movement of thedispensing head 24 a along the x-axis.

Gantry system 22 a further includes two nut blocks 66 and 68 that areslidably movable along the rails mounted under the horizontal supportmembers 26 and 28. Each of the nut blocks is coupled to one of themotors 74, 76 through a respective lead screw 70, 72. The nut blocks canbe separately driven by the motors using the lead screws to move the nutblocks along the y-axis. The carriage 60 is connected to each nut block66, 68 with respective rigid trailing arms 80, 82 that are pivotallyconnected at one end to one of the nut blocks and at the other end tothe carriage 60. As explained in greater detail in U.S. Pat. No.5,903,125, which is hereby incorporated by reference in its entirety,the dispensing head 24 a may be positioned along the x and y axes bymoving the nut blocks along the y-axis using motors 74 and 76. Motors 74and 76, as well as the z-axis motor coupled to the carriage 60, arecontrolled by the primary system controller located in the lowercompartment.

The dispensing heads 24 a, 24 b, 24 c and 24 d may be implemented usinga number of different dispensing heads or pumps including thosedisclosed in commonly owned U.S. Pat. No. 6,119,895, and in commonlyowned U.S. Pat. No. 6,085,943, each of which is hereby incorporated byreference in its entirety.

The gantry systems 22 a, 22 b, 22 c and 22 d provide a significantadvantage in the dispensing system 10. As described in U.S. Pat. No.5,903,125, the ratio of the working area beneath the gantry system tothe total width of the gantry system is much greater for the gantrysystems described above than for typical x/y gantry systems. Thisreduces the time required to move a work product between work positionsin the multiple head dispensing system, and also reduces the totalfootprint of the dispensing system 10.

The conveyor system 20 will now be described in greater detail withreference to FIGS. 3 and 4. FIG. 3 shows a perspective view of theconveyor system 20. FIG. 4 shows a top view of the conveyor system 20with several elements removed for clarity. Additionally, FIG. 4 showsthe rail position control system 300 for adjusting conveyor rails 90,92, 94 and 96 of the conveyor system 20 to accommodate differently sizedsubstrates. Although, the conveyor system 20 includes two lanes, itshould be understood that in other embodiments of the present invention,a conveyor system may include more than two lanes or may include only asingle lane.

The conveyor system 20 includes four rails 90, 92, 94 and 96 that definetwo lanes, which are respectively identified as a front lane and a backlane having lane widths w1 and w2. The front and back lanes are used fortransporting substrates, such as circuit boards, integrated circuitcarriers and other substrates into, through, and out of the dispensingsystem 10.

The conveyor system 20 further includes four substantially identicalmodular conveyor sections 98. The conveyor sections 98 define eight workareas 200, 202, 204, 206, 208, 210, 212, and 214, as shown in FIG. 4.Support blocks 102 are used to hold the conveyor sections 98 togetherand to hold the conveyor sections 98 in place on the work surface 18 ofthe dispensing system 10. Each of the rails 90, 92, 94 and 96 of theconveyor system 20 further include an end adapter 100, which is locatedat each end of each of the rails 90, 92, 94 and 96. The rails 90, 92, 94and 96 are connected by tracks or cross-members 104 a, 104 b, 104 c, 104d and 104 e, which support and hold the rails 90, 92, 94 and 96 in asubstantially parallel alignment with respect to each other.

The front and back lanes of the conveyor system 20, which respectivelyinclude lane widths w1 and w2, may be adjusted by moving the rails 90,92, 94 and 96 to different positions along the tracks or cross-members104 a, 104 b, 104 c, 104 d and 104 e. As a result of moving the rails90, 92, 94 and 96 to different positions along the tracks orcross-members 104 a, 104 b, 104 c, 104 d and 104 e, the lane widths w1and w2 are also adjusted to accommodate differently sized substrates. Inan embodiment, the width w1 of the front lane may be different than thewidth w2 of the back lane.

Each of the conveyor sections 98 of the conveyor system 20 furtherincludes a conveyor belt 106 that may be implemented as a continuousbelt consisting of black neoprene over a cotton cord or may beimplemented as a series of links. The conveyor belt 106 is wrappedaround four pulleys 108 a, 108 b, 108 c and 108 d. A total of eightdrive shafts, four drive shafts 110 and four drive shafts 111, are usedto operate the conveyors. Each of the drive shafts is coupled to its ownmotor 112 to allow independent operation of each pair of conveyorsections. Operation of each of the motors is controlled by the primarysystem controller. For simplification, only two of the motors 112 areshown in FIG. 3.

Four drive shafts 110 are used to drive the conveyor segments in theback lane, and four drive shafts 111 are used to drive the conveyorsegments in the front lane. For uniformity and ease of manufacturing,all eight drive shafts are substantially identical, and each of thedrive shafts 110 extends through all four rails. Cogs are selectivelyadded to the lower pulleys 108 a and 108 d to cause the pulleys torotate with the drive shafts. In the conveyor system 20, for allconveyor sections 98 in the back lane, the lower pulleys closest to theinput side of the conveyor system include a cog, and the lower pulleysclosest to the output side of the conveyor system do not have a cog. Forall conveyor sections 98 in the front lane, the lower pulleys closest tothe input side of the conveyor system do not include a cog, and thelower pulleys closest to the output side of the conveyor system doinclude a cog. This implementation allows each pair of conveyorsections, defining one of the work areas, to operate independently. Asunderstood by those skilled in the art, to meet specific applicationdemands, the cogs may be arranged in other configurations.

Each of the end adapters 100 has a conveyor 101 that is coupled to theconveyor 106 of the adjacent conveyor section using an extension piece103 so that each conveyor 101 is driven by the conveyor 106 of theadjacent conveyor section.

As described above, in one embodiment, all of the conveyor sections 98are substantially identical. In addition, each conveyor section 98 issymmetrical about a vertical axis perpendicular to the direction ofconveyor travel and passing through the middle of the conveyor section.This allows identical conveyor sections to be used on opposite rails ofthe same lane, and at any position (i.e., at the input end, output end,or in the middle) in any of the rails.

In the embodiment shown in FIG. 4, the rail position control system 300includes at least one camera 305 that is mounted on a mounting surface,such as on the dispensing head 24 a, which is located in close proximityto the conveyor system 20. As discussed above, the dispensing head 24 ais coupled to lead screws 70 and 72, which are adapted to precisely movethe dispensing head 24 a and camera 305 along the y-axis. An encoder 41is coupled to the lead screws 70 and 72 to determine the preciseposition of the dispensing head 24 a and camera 305 along the y-axis. Inother embodiments, other cameras that are similar to the camera 305 canbe similarly mounted on the dispensing heads 24 b, 24 c or 24 d.

The rail position control system 300 further includes a computer system310 that is operatively coupled to the camera 305, to the encoder 41 andto a rail adjustment motor 320. The rail adjustment motor 320 is furthercoupled to at least one conveyor rail 90, 92, 94 and/or 96 of theconveyor system 20. In an embodiment, the rail adjustment motor 320 iscoupled to the conveyor rails 90 and 96.

Each of the rails 90, 92, 94 and 96, as shown in FIG. 4, respectivelyinclude at least one registration mark 307 a, 307 b, 307 c and 307 d. Inan embodiment, the registration marks 307 a, 307 b, 307 c and 307 d caneach include at least one machined cavity, tapped hole with a screwthreaded therein and/or a colored marking. The registration marks 307 a,307 b, 307 c and 307 d located on each of the respective rails 90, 92,94 and 96 can be uniquely positioned on the rails 90, 92, 94 and 96 touniquely identify a particular rail 90, 92, 94 or 96. For example, theregistration mark 307 a can be centered at a position on the rail 90that is three inches from a first end 90 a of the rail 90, theregistration mark 307 b can be centered at a position on the rail 92that is four inches from a first end 92 a of the rail 92, theregistration mark 307 c can be centered at a position on the rail 94that is five inches from a first end 94 a of the rail 94 and theregistration mark 307 d can be centered at a position on the rail 96that is six inches from a first end 96 a of the rail 96. Tthe uniquepositioning of the registration marks allows the rail position controlsystem to identify a rail based on the location of the registration markon the rail.

FIG. 5 shows a simplified side view of a portion of the dispensingsystem 10 as well as a single lane (e.g. front lane) of the conveyorsystem 20 of FIG. 4. During operation of the rail position controlsystem 300, as shown in FIG. 5, the camera 305 is moved along the y-axisby controlling the actuation of the lead screws 70 and 72 to move thedispensing head 24 a and camera 305, which is mounted on the dispensinghead, to center the camera on the registration mark 307 a. The relativeposition of the camera, while centered on the registration mark 307 a,is determined by the encoder 41 which provides a first position signalto the computer system 310 for processing. The camera 305 is again movedalong the y-axis by controlling the actuation of the lead screw 39 tomove the dispensing head 24 a and camera 305 until the camera iscentered on the registration mark 307 b. The relative position of thecamera 305 is again determined by the encoder 41 and a second positionsignal is provided to the computer system 310 in a similar manner asthat described above. The computer system 310 processes the first andsecond position signals to determine a spacing located between the rails90 and 92 or a rail spacing value. In other embodiments, one of therails may be at a known fixed position, and the camera only looks at theregistration mark on the movable rail to determine the lane width.

The computer system 300 further processes the rail spacing value andgenerates a rail spacing adjustment value. The rail spacing adjustmentvalue is communicated, via control signals, to the rail adjustment motor320 to actuate the motor to move the conveyor rail 90 of the conveyorsystem 20 a distance. The distance that the conveyor rail 90 is moved isequal to the rail position adjustment value, which adjusts the spacinglocated between the rails 90 and 92 of the conveyor system 20. Althoughthe above described operation includes adjusting the spacing of rails 90and 92 of the front conveyor lane of the conveyor system 20, a similarprocess may be used to adjust the spacing of rails 94 and 96 of the rearconveyor lane of the conveyor system 20.

In other embodiments of the present invention, the camera 305 may beused: to locate and view other registration marks located on substratesloaded into the dispensing system 10 for alignment purposes, to inspectsubstrates after material has been dispensed, or some other operationhas been performed, and to identify a type of substrate loaded into thedispensing system 10.

In other embodiments of the present invention, the camera 305 mounted onthe dispensing head 24 a can be replaced with an opticaltransmitter/receiver unit. Further, the registration marks 307 a, 307 b,307 c and 307 d can each be encoded with an optically communicable railidentifier value that uniquely identifies each of the respectiveconveyor rails 90, 92, 94 and/or 96. The rail identifier valueassociated with each rail can be communicated to the computer system310, via the optical transmitter/receiver unit, to enable the computersystem to identify a particular rail 90, 92, 94 and/or 96 and todetermine the position of the particular rail 90, 92, 94 and/or 96 withrespect to the other rails 90, 92, 94 and/or 96. The computer system 310can further respond to the values representing the respective widths w1and w2 of the front and back lanes of the conveyor system 20 bycontrolling the rail width adjust motor 320 to move at least one rail90, 92, 94 and/or 96 to adjust the lane widths w1 and/or w2 toaccommodate different size substrates.

In embodiments described above, a camera is mounted on the same gantrysystem that supports a dispensing head. In other various embodiments, acamera may be mounted on a separate gantry or in a fixed position abovethe conveyor system. In one embodiment, the camera is mounted at a fixedposition at a height above the conveyor system such that the camera isable to view the rails of a conveyor system to determine the distancebetween the rails using a single image.

Having thus described at least one illustrative embodiment of theinvention, various alterations, modifications and improvements willreadily occur to those skilled in the art. Such alterations,modifications and improvements are intended to be within the scope andspirit of the invention. Accordingly, the foregoing description is byway of example only and is not intended as limiting.

1. A method of controlling a conveyor system configuration, having afirst rail and a second rail, to accommodate a plurality of differentlysized substrates, the method comprising: positioning a camera to captureat least one image of the conveyor system; determining a distancebetween the first rail and the second rail based at least in part on theat least one image; comparing the distance determined with a desireddistance; and moving at least one of the first rail and the second railto set the distance substantially equal to the desired distance.
 2. Themethod of claim 1, wherein positioning a camera includes positioning thecamera to a first position over the first rail to capture an image ofthe first rail; and positioning the camera to a second position over thesecond rail to capture an image of the second rail.
 3. The method ofclaim 2, wherein determining a distance includes determining a distancebetween the first position and the second position.
 4. The method ofclaim 1, wherein the second rail has a registration mark at a positionon the second rail, and wherein the method further includes identifyingthe second rail based on the position of the registration mark.
 5. Amethod of controlling a conveyor system configuration having a firstlane defined by a first rail and a second rail and a second lane definedby a third rail and a fourth rail, each lane being capable ofaccommodating a plurality of differently sized substrates, the methodcomprising: positioning a camera to capture at least one image of thefirst lane and the second lane; determining a distance between the firstrail and the second rail of the first lane and a distance between thethird rail and the fourth rail of the second lane based at least in parton the at least one image; comparing the distances determined of thefirst and second lanes with predetermined distances of the first andsecond lanes, respectively; and moving at least one of the first railand the second rail of the first lane and at least one of the third railand the fourth rail of the second lane to set the distancessubstantially equal to the predetermined distances of the first andsecond lanes.
 6. The method of claim 5, wherein positioning a cameraincludes positioning the camera to a first position over the first railto capture an image of the first rail; positioning the camera to asecond position over the second rail to capture an image of the secondrail; positioning the camera to a third position over the third rail tocapture an image of the third rail; and positioning the camera to afourth position over the fourth rail to capture an image of the fourthrail.
 7. The method of claim 6, wherein determining the distances of thefirst and second lanes includes determining a distance between the firstposition and the second position and a distance between the thirdposition and the fourth position.
 8. The method of claim 5, wherein thesecond rail and the fourth rail each have a registration mark at aposition on the rail.
 9. The method of claim 8, wherein the methodfurther includes identifying the second and fourth rails based on theposition of the registration marks.
 10. A method of dispensing a viscousmaterial on an electronic substrate, the method comprising: receiving anelectronic substrate; controlling a conveyor system configuration,having a first lane defined by a first rail and a second rail, toaccommodate a plurality of differently sized substrates; positioning acamera to capture at least one image of the first lane of the conveyorsystem; determining a distance between the first rail and the secondrail of the first lane based at least in part on the at least one imageof the first lane; comparing the distance determined of the first lanewith a predetermined distance of the first lane; moving at least one ofthe first rail and the second rail of the first lane to set the distanceof the first lane substantially equal to the predetermined distance ofthe first lane; dispensing viscous material on the substrate; andejecting the substrate.
 11. The method of claim 10, wherein positioninga camera includes positioning the camera to a first position over thefirst rail to capture an image of the first rail; and positioning thecamera to a second position over the second rail to capture an image ofthe second rail.
 12. The method of claim 11, wherein determining adistance of the first lane includes determining a distance between thefirst position and the second position.
 13. The method of claim 11,wherein the second rail has a registration mark at a position on thesecond rail, and wherein the method further includes identifying thesecond rail based on the position of the registration mark.
 14. Themethod of claim 11, wherein the conveyor system configuration furthercomprises a second lane defined by a third rail and a fourth rail. 15.The method of claim 14, further comprising: positioning the camera tocapture at least one image of the second lane of the conveyor system;determining a distance between the third rail and the fourth rail of thesecond lane based at least in part on the at least one image of thesecond lane; comparing the distance of the second lane with apredetermined distance of the second lane; and moving at least one ofthe third rail and the fourth rail of the second lane to set thedistance of the second lane substantially equal to a predetermineddistance of the second lane.
 16. The method of claim 15, whereinpositioning the camera includes positioning the camera to a thirdposition over the third rail to capture an image of the third rail; andpositioning the camera to a fourth position over the fourth rail tocapture an image of the fourth rail.
 17. The method of claim 16, whereindetermining the distance of the second lane includes determining adistance between the third position and the fourth position.
 18. Themethod of claim 15, wherein the fourth rail has a registration mark at aposition on the fourth rail.
 19. The method of claim 18, wherein themethod further comprises identifying the fourth rail based on theposition of the registration mark on the fourth rail.